Abstract Background Third-degree atrioventricular (AV) block can result in sudden cardiac death if no reliable escape rhythm is present. Here, we report a case of an 86-year-old female patient who developed a third-degree AV block leading to cardiac arrest. Surprisingly, sinus rhythm returned after 4 min of asystole, and she showed complete neurological recovery. Case summary Emergency services were contacted by the husband of an 86-year-old woman after she was found unconscious. Ambulance personnel diagnosed a third-degree AV block without an escape rhythm and transcutaneous pacing was started. At arrival on the emergency ward, pacing was inadequate, resulting in absence of circulation for ∼10 min. After consultation with the family, the patient turned out to have signed a ‘do not resuscitate’ order. Given the impression that the considerable delay deemed favourable neurological recovery unlikely, it was decided together with the family to stop the resuscitation. Subsequently, she had an intermittent junctional escape rhythm but eventually developed a documented asystole of more than 4 min. Against all expectations, she regained sinus rhythm and fully recovered. Eventually, a pacemaker was implanted and she was discharged home without neurological sequalae of the cardiac arrest. Discussion Autoresuscitation, also known as the Lazarus syndrome, is the spontaneous return of circulation after cardiac arrest and is incidentally seen after failed cardiopulmonary resuscitation (CPR). Autoresuscitation in the absence of CPR is highly unusual, but could, in this case, be due to the total AV block as the cause of the cardiac arrest.